Software systems can be complex. And what is the best way to represent complex systems? Through models, right? Complex software systems can be made more comprehensible by using software modelling techniques. Agile software systems use agile modelling to ensure that the vision and goal of the system is made clear, logical and understandable to the entire team. In this blog, we attempt to understand what the primary goal in agile modelling and various other factors is associated with it.
What Is Agile Modelling?
Agile modelling is a set of software modelling practices, values and principles that can be applied on software development projects. It is defined by AgileModeling as “a practice-based methodology for effective modelling and documentation of software-based systems.” Agile modelling follows the values of Agile software development and offers an effective and lightweight method for modelling.
Agile modelling helps to create a customizable model for software development that developers can use. It is also flexible enough to be changed to meet future requirements.
Phases of the Agile Model
Before we dive deep into Agile modelling, let’s look at the phases in the agile software development model.
The need for the project must be identified, its end goals and objectives are identified, and the time and cost aspects are calculated to justify the need for the project.
Requirements are defined after liaising with the stakeholders.
The product is built incrementally and iteratively. The end result of each iteration is a workable product.
Testing is built into the development where the product is tested for bugs or performance issues.
The product is deployed in the production environment.
This is an important phase in the product development lifecycle which is done once the product is released. The team receives feedback on the product and takes care of any issues that need addressing.
The Need for a Better Modelling Methodology:
System development is complex and prone to a whole lot of errors. It is estimated that failure rates are as high as 50-75%. Software modelling systems aim to reduce these errors associated with system development. Agile modelling offers a set of core principles and best practices that strive to improve the rate of system development failures.
Agile modelling offers simplicity. Complex systems can be overwhelming and often the goal and end objective of what the project is trying to achieve is lost. An effective modelling technique can help in achieving this simplicity and better communicate the project goals and objectives.
Models also help us visualize the system as it should be. They guide us in the way the system should be built in order to be most effective by offering us a template which will guide us during development. The more complex the system is the more prone it is to error. Models helps us better visualize and interpret complex systems while also helping us with documenting the decisions we have made.
Agile Modelling Core Principles:
Just like Agile is based on values and principles that help make development work more adaptable, flexible and less risky, so is Agile modelling based on certain core principles. These core principles make Agile modelling effective and easy and help creating systems that espouse the values of Agile.
The core principles that need to be considered while building Agile models are:
- Have a purpose: When you model, make sure you keep in sight what you are developing and who you are developing it for.
- Keep it simple: Your model should be simplistic and convey the simplest solution. You can always refine your models when needed.
- Be open to change: Your project is not static, it changes, and it grows. Your model too might need changing based on the changes that happen in the project. Be open to change and accommodate them in your model.
- Leave proper references: Your model should be easy enough for someone else to be able to add to it or change it after you leave the project. Make sure your documentation and model can be tweaked easily.
- Ensure stakeholder satisfaction: Your model should support development which will help ensure maximizing value for the customer. After all customer satisfaction is the most important goal of agile software development.
- Choose the best fit: You may use multiple models and solutions; choose the best fit according to a given situation.
- Ensure great quality: The quality of work should satisfy not just the person creating it but also those who it is being created for and those who may work on it later. So, make sure that you are offering the best quality possible.
- Rapid feedback: Just like rapid feedback is an essential part of Agile software development, so should getting rapid feedback on your model be essential as this will help you refine and tweak errors. Like Agile follows software development in short iterations, it is best if you model a little, take feedback and then add to it.
- Go easy on documentation: Too much documentation will again end up confusing the development team. On the other hand, too little documentation may leave gaps in understanding. So, make sure that your documentation is just right.
Agile Modelling Embraces Five Values:
The five values of Agile Modelling are:
- Communication: Effective models help to improve communication between all those involved in the project, including stakeholders.
- Simplicity: The model is meant to make software development easier, and you should follow simple guidelines for developing models. You can create a basic model that fulfils all your requirements and build on it.
- Feedback: Feedback is an essential part of creating models and improving them. Get feedback early and frequently.
- Courage: Not all your ideas may be accepted, and you may have to change them. You need to have the courage to accept that and change or adapt your ideas.
- Humility: Everyone involved in a project may add their own expertise and bring in their own ideas to the table. Successful developers must have the humility to accept ideas from others and build on them. After all agile is all about teamwork and taking suggestions from team members and stakeholders shows that you have the humility to improve and accept new ideas.
Agile Modelling Best Practices:
Each organization has its own set of best practices when it comes to agile modelling. But the generally accepted best practices are listed below:
- Involve stakeholders: Stakeholder participation is an important aspect of modelling as their inputs received at the right time can help take the right decisions. This ensures that they are involved in the development process throughout.
- Envision the project architecture: A high level architecture modelling carried out at the beginning of the project will help map out a technical strategy for the development process.
- Iteration Modelling: Modelling is also carried out at the beginning of each iteration to plan out activities.
- Just enough: A model need not have too much information but just enough to get the work at hand accomplished.
- Lookahead Modelling: This may be done in order to reduce the risk associated with the project.
- Model Storming: Model storming on a Just in Time basis helps to identify the details for a requirement or think through a design issue. This is generally only a few minutes in duration.
- Using multiple models: As a developer who created models, you need to have expertise and knowledge of multiple models so that you can apply the right one to the right situation.
- Prioritize requirements: Your model should also reflect priority items as defined by the stakeholders so as to ensure maximum returns.
- Identify Requirements: This is done at the start of a project to get an overview of the priority requirements and to create the scope of the project.
- Test Driven Development: TDD is an Agile approach that falls under the Just in Time development method. This involves writing a single test and writing just enough code to fulfil the test.
What Are the Advantages of Using Agile Modelling, and What Are the Disadvantages?
- Helps enhance project flexibility by provisioning easy handling of changes
- Facilitates communication between team members and stakeholders
- Reduces development time and helps in faster release of software
- Ensures rapid and continuous delivery of releasable and workable product
- Modelling requires a fair level of experience and development skills
- Modelling for larger projects may prove challenging as it is difficult to estimate the amount of time required at the start of the development cycle.
- If the model is not detailed enough it may lead to confusion between teams and a lag between phases.
As we race towards better and bigger technology, the systems and applications around us are getting more and more complex. But unfortunately, these come with a whole set of risks and are prone to errors and failures. Agile modelling helps a great deal to reduce these errors and give a breakdown of the structure that everyone can understand and build upon.